HP StorageWorks 8000 NAS - Manual (Page 150)

148 Enabling Virus and Backup Software
The table below explains each of this window’s fields:
Snapshot Behavior: Per-volume Snapshot Backup
The HP NAS operating system lets you take a snapshot (checkpoint) of an
entire volume so that you can create a point-in-time copy of all files.
OmniBack II agent for HP NAS helps you create a snapshot before backup,
then backs up the files from this snapshot volume. After you perform a
backup, the snapshot is removed.
Note that OmniBack II agent creates an individual snapshot for each volume
just before a backup. Therefore, a point-in-time copy applies only to a single
volume. If your application stores data in two or more volumes, the snapshot
backup will not provide a consistent point-in-time copy of the files.
By default, the size of a snapshot volume is 10 percent of the original
volume's size. The snapshot volume size must be large enough to
accommodate all of the changed files during the backup task. If a snapshot
exists for a long time and many changes occur on the original file system
during this time, the snapshot volume can become full. Therefore, OmniBack II
provides a variable you can use to set the size of a snapshot volume. This
variable (OB2HPNASSNAPSHOTSIZE) resides in the .omnirc file. The
Command View NAS web interface provides an interface in which you can
set this variable.
Field Description
Backup Snapshot Behavior Drop-down list that controls the behavior of snapshots for the backup
session. There are three selections for this field:
■ Utilize a snapshot when performing the backup. If this selection is
chosen, make sure that the snapshot volume percentage field is large
enough to accommodate the snapshot for the backup.
■ Perform the backup utilizing the snapshot mechanism, but if the
snapshot fails, the backup will continue.
Perform the backup without utilizing snapshots (default).
Backup Snapshot Volume
Percentage
Defines the size of the snapshot in terms of the percentage of the
original volume's space. Set the value between 10 and 100 percent (10
- 100).
OmniBack II Port Number The default port number is 5555, when this value is changed the agent
will be restarted. Do not change during a backup.